When fluids flow through a conduit such as a pipeline or a production line from a wellhead, friction results, requiring energy increases for the driving force Sometimes it is desirable to increase the flow rate of fluids through conduits, but this cannot always be satisfactorily accomplished by installing additional booster pumps. In production lines, particularly offshore, the weight and cost of additional pumping capacity can become prohibitive. The flow rate of the fluid through the conduit can alternatively be increased by reducing the friction of the fluid in the conduit.
One method of reducing friction loss in fluids moving through a conduit is to inject into the fluid a substance which is capable of reducing the pressure or friction loss of the fluid moving through the conduit. Such substance must not only reduce the friction loss of the fluid, but must be compatible with the fluid and must not interfere with the intended use of the fluid.
Since the friction reducer must be compatible with the fluid to which it is added, water soluble polymers are ordinarily used where the material being transported is water or a mixture of water and a hydrocarbon oil, particularly when the mixture contains substantial amount of water.
Water soluble polymers are preferably formulated and used as an emulsion where the polymer molecules are partially solubilized in water droplets and the water droplets are emulsified in a hydrocarbon phase. However, when such emulsions are used to reduce friction loss of a saline liquid in a conduit or pipe it has been found that performance of the friction reducing materials is lower than expected. It appears that the reason for this lower performance is that a part or most of the polymer in the emulsion is not activated (inverted) in the flowing fluid. As a result, the polymer is not fully utilized to reduce friction loss. After initial injection of the emulsion whatever portion of the polymer that does not activate immediately remains inactivated even after a substantial period of time.
It would be desirable to provide a method for preactivating (inverting) the polymer in a polymer emulsion prior to introduction of the emulsion into a pipeline or conduit containing a flowing saline liquid.